The present invention relates to integrated circuit (IC) device assembly and, more particularly, to lead frames for semiconductor packages.
Many current semiconductor assembly processes include a down bonding process in which a die is electrically connected to a down bond area of a lead frame with a bond wire. However, before the down bonding process, the down bond area of the lead frame may have been contaminated by die attach material such as solder from a die attach process.
FIG. 1 shows a partially assembled semiconductor device 10 having a die 12 attached on a die attach area 14 of a lead frame 16, where the die attach process caused contamination 18 on a down bond area 20 of the lead frame 16. A bond wire 22 electrically connects the die 12 to the down bond area 20 of the lead frame 16. Such contamination 18 on the down bond area 20 can cause the wire bond to have a low wire peel strength.
One solution to prevent contamination of the down bond area 20 is to half etch a groove between the down bond area 20 and the die attach area 14 to prevent the die attach material from leaking into the down bond area 20. However, for devices that have a small lead frame and a large die, there may not be sufficient space for groove formation. Furthermore, the half etching process can be expensive. Accordingly, it would be advantageous to find a new way to prevent contamination of the down bond area from die attach material.